Which polymer is used as a lubricant and an insulator?

Which of the following statements is false for biodegradable polymers?

Consider the following sequence of reactions.
$2 CH_3Cl + Si$ $\xrightarrow[573 \ K]{Cu} X$ $\xrightarrow{H_2O} Y$ $\xrightarrow{\text{Polymerization}} Z$
The repeating structural unit in $Z$ is

The number average molecular mass of a polymer that contains $15$ molecules with each of mass $8,000$ and $15$ molecules with each of mass $80,000$ is: (in $,000$)

Natural rubber is a polymer of ....

Which of the following polymers contains an ester linkage?